The invention relates to a gear selector unit for a transmission in motor vehicles, and particularly to a gear selector unit for indirectly operated transmissions.
In indirectly operated transmissions, the gears are engaged by operating cylinders, which are generally located in the transmission. To control the supply of fluid pressure to the operating cylinders, solenoid valves are provided. These solenoid valves are controlled in accordance with the position of a gear shift lever, and may be further influenced by other data, such as the gear engagement and disengagement speed. The data are generally put into an electronic system, and must therefore be available as electrical values. It is therefore necessary to sense the position of the gear selector lever, which corresponds to the desired gear, and to convert it into a corresponding electrical signal.
Sensing the position of a gear shift lever by means of microswitches is already known. The microswitches here, however, are not activated directly by the gear shift lever, but by a gear shift lever shaft which can be adjusted by the shift lever. By means of the signals of the microswitches, there is a servo-support of the gear-shifting process by means of an electronic system and an operating cylinder.